Category Archives: genetics

Medieval Historians Taking Genomics into Account

At the International Congress on Medieval Studies at Kalamazoo (Kzoo) last month, I couldn’t help feeling that we have reached a turning point. I went to four sessions that engaged in genomics, human and/or bacterial, in some way. Granted, these are a tiny proportion of the 500+ sessions offered, but I have learned that if you can string together so many sessions on any topic related to your work, it’s a really good Congress.

Before and After 1348: Prelude and Consequences of the Black Death session, Kalamazoo, 2017. Pictured: Monica Green and Robert Hymes (Photo: Nukhet Varlik, used with permission)

The tone was set in the very first session when Philip Slavin brought up human epigenetics in his discussion of 14th-century famine. This was followed the next day with three sessions on the Black Death and 14th-century crisis. The two Contagions society sessions went very well. Carenza Lewis talked about her ceramics landscape survey that showed how deep the 14th-century demographic loss actually was. Fabian Crespo introduced the audience to the human immune landscape and how it can be fruitfully approached (including by epigenetics).  I will post on the roundtable on Bruce Campbell’s The Great Transition later this summer. The third plague session, Before and After 1348,  organized by Monica Green focused on Asia and generated a vigorous discussion.   I also attended a fifth session that focused on more traditional biological anthropology, ie. mostly osteology.

This turn hasn’t come all of a sudden. Historians began paying more attention to bacterial genomics a little over a decade ago when plague aDNA first hit the news. Michael McCormick, Lester Little, and Monica Green have all been instrumental in bringing science to the attention of historians. Three edited volumes stand out for putting genomics in front of historians: Lester Little’s Plague and the End of Antiquity: The Pandemic of 541-750 (2007), Linda Clark and Carol Rawcliffe’s Society in the Age of Plague (2013), and Monica Green’s Pandemic Disease in the Medieval World: Rethinking the Black Death* (2015).

On the other hand, scientists have also edited collections of papers that should make the science more accessible to historians. Didier Raoult and Michel Drancourt have edited two volumes, Paleomicrobiology (2008) and Paleomicrobiology of Humans (2017). Ruifu Yang and Andrey Anisimov edited a more technical volume, Yersinia pestis: Retrospective and Perspective (2016) that should summarize the state of the science  (as of 2016) for more advanced readers in the humanities.

Of the monographs, the historian’s usual primary venue,  books addressing genomics or using genomics as a springboard are limited. With at least three appearing in 2016 by Nükhet Varlik, Ole Benedictow, and Bruce Campbell, this should change soon. At this point, I should mention that genomics is already becoming useful to historians of other diseases, especially leprosy and tuberculosis. Historians are also becoming reinvigorated to provide context for plague and other diseases that may be of interest to geneticists and biological anthropologists. Varlik’s edited collected Plague and Contagion in the Islamic Mediterranean  (2017) is the most recent to provide context for a variety of diseases in an understudied area.

*Green’s volume was first published as a double inaugural issue of the journal The Medieval Globe and then published as a hardback book by ARC Medieval Press.

Expanding the Historical Plague Paradigm

When the first complete genomic sequence of Yersinia pestis was published on October 4, 2001 the world was naturally focused elsewhere, on anthrax bioterrorism — the Amerithrax incident was then in its second week– and the September 11 attacks were just over three weeks old. As the world redeveloped bioterrorism assessments and plans, plague was placed on lists along with anthrax, smallpox and yes, ebola as agents of national security concern and response.  Although plague produced more annual cases than most agents on the category A bioterrorism list, it was placed on the list primarily based on its historical reputation and past attempts to weaponize it (also based on its reputation). Yet, in 2001 there was a fierce debate ranging among historians and others on whether Yersinia pestis was the agent of the Black Death at all.

It would take another ten years before genomics would revolutionize our understanding of the historical plague. On October 12, 2011 the first draft sequence of an ancient plague genome was published. Finally, adding to the detection of Yersinia pestis DNA tests previously done on remains, the draft sequence isolated from the East Smithfield Black Death cemetery in London solidified consensus that Yersinia pestis is the agent of the Black Death pandemic.  Meanwhile, the phylogenetic tree of Yersinia pestis had been constructed based on the genetic sequence of isolates from all over the globe. Ancient and modern Yersinia pestis genomes were opening a new window into the history of the species.

As fundamental as genomic analysis is to the new understanding of historical plague, it is a skeleton of data that is open to many different historical interpretations. Science can’t adequately explain the historic plague epidemics alone; it takes historical context. In the inaugural double issue of The Medieval Globe,  Pandemic Disease in the Medieval World: Rethinking the Black Death (open access) begins this process. The eleven articles in this issue take the genetic identification of Yersinia pestis  as the agent of the Black Death as foundational and integrate modern biological and epidemiological information into a new global Old World assessment of the history of the Black Death and subsequent epidemics. Each of these articles lays the groundwork for future interdisciplinary work between historians, anthropologists, biologists, epidemiologists and others.

In my own contribution to this issue, “The Black Death and the Future of the Plague” I discuss why plague is still important in the modern world and for our future. Plague has played an integral role in the development of the re-emerging infectious diseases paradigm and is an agent of biosecurity concern. I review the current state of plague around the world, what we have learned about plague epidemiology and transmission, and how it can be applied to historic epidemics. I also make my case for why the study of the entire history of plague is uniquely important and why the sciences and humanities must move forward together.  I hope we can engage in a discussion on these issues here in the comments section, on twitter or by email.

My own interest and awareness of the issues surrounding the study of the plague was transformed when I had the great fortune to be invited by Monica Green to participate in a session at the American Historical Association annual meeting in New Orleans, January 2013. The group of plague scholars gathered there has largely remained in contact and expanded our network into an informal working group that has enriched all of our scholarship.  No one can become fully conversant with all of the disciplines involved in the study of even one epidemic, much less the entire history of the plague.  Working in disciplinary seclusion will not produce a satisfying paradigm or widespread consensus. It takes work, patience and some tolerance of how other disciplines work, but I have found it to always be worth it. I hope you will agree.

Some references for the milestones mentioned:

Parkhill, J., Wren, B. W., Thomson, N. R., Titball, R. W., Holden, M. T., Prentice, M. B., et al. (2001). Genome sequence of Yersinia pestis, the causative agent of plague. Nature, 413(6855), 523–527. doi:10.1038/35097083

Morelli, G., Song, Y., Mazzoni, C. J., Eppinger, M., Roumagnac, P., Wagner, D. M., et al. (2010). Yersinia pestis genome sequencing identifies patterns of global phylogenetic diversity. Nature Genetics, 1–20. doi:10.1038/ng.705

Little, L. K. (2011). Plague Historians in Lab Coats. Past & Present, 213(1), 267–290. doi:10.1093/pastj/gtr014

Bos, K. I., Schuenemann, V. J., Golding, G. B., Burbano, H. A., Waglechner, N., Coombes, B. K., et al. (2011). A draft genome of Yersinia pestis from victims of the Black Death. Nature, 1–5. doi:10.1038/nature10549

Pandemic Disease in the Medieval World: Rethinking the Black Death. Edited by Monica Green. The Medieval Globe, 1 (1), 2014.

Autumn Reading

Autumn 2014

So much for my plan to do monthly reading updates. I think quarterly might be more feasible. It seems like the fall has flown by and was not as productive as I would have liked. Isn’t that always the way?

So I’m currently working my way through Cameron’s Anglo-Saxon Medicine and then next up will be the brand new second edition of Mitchell’s A History of the Later Roman Empire AD 284-641.

Books finished:
  • Matilda Holmes, Animals in Saxon and Scandinavian England: Backbones of Economy and Society. Sidestone press, 2014 (reviewed here)
  • Prokopius, The Secret History and Related Texts. Anthony Kaldellis, ed. Hackett, 2010.
  • David Quammen. Ebola: A Natural and Human History of a Deadly Virus. 2014. (excerpted, adapted and updated from his Spillover)
Notable Papers
  • Setzer, T. J. (2014). Malaria detection in the field of paleopathology: A meta-analysis of the state of the art. Acta Tropica, 140, 97–104. doi:10.1016/j.actatropica.2014.08.010 (summarized here)
  • Christina Lee. (2014). Invisible enemies: the role of epidemics in the shaping of historical events in the early medieval period in. Social Dimensions of Medieval Disease and Disability, 1–17.
  • Sallares, R. (2006). Role of environmental changes in the spread of malaria in Europe during the Holocene. Quaternary International, 150(1), 21–27. doi:10.1016/j.quaint.2006.01.005
  • Sallares, R., Bouwman, A., & Anderung, C. (2004). The spread of malaria to Southern Europe in antiquity: new approaches to old problems. Medical History, 48(3), 311–328.
  • Collins, W. E., & Jeffery, G. M. (2007). Plasmodium malariae: Parasite and Disease. Clinical Microbiology Reviews, 20(4), 579–592. doi:10.1128/CMR.00027-07
  • Schreg, Rainer. (2014) “Ecological Approaches in Medieval Rural Archaeology” European Journal of Archaeology, 17 (1), 83-119.
  • Flaherty, E. (2014). Assessing the distribution of social–ecological resilience and risk: Ireland as a case study of the uneven impact of famine. Ecological Complexity, 19, 35–45. doi:10.1016/j.ecocom.2014.04.002
  • SHARPE, W. D., &  Isidore of Seville. (1964). Isidore of Seville: the Medical Writings. An English Translation with an Introduction and Commentary. Transactions of the American Philosophical Society, New Series, 54(2), 1–75.
  • Carter, R., & Mendis, K. N. (2002). Evolutionary and Historical Aspects of the Burden of Malaria. Clinical Microbiology Reviews, 15(4), 564–594. doi:10.1128/CMR.15.4.564-594.2002
I’ve also spent quite a bit of time this autumn reading the pre-print editions of the contributions to Pandemic Disease in the Medieval World: Rethinking the Black Death edited by Monica Green in the inaugural edition of The Medieval Globe, which I’m honored to be a contributor to. Watch this space for more news on this special issue very soon.